JEE Main · 2023 · Shift-IImediumBIO-066

A tetrapeptide 'x' on complete hydrolysis produced glycine (Gly), alanine (Ala), valine (Val), leucine (Leu) in…

Biomolecules · Class 12 · JEE Main Previous Year Question

Question

A tetrapeptide 'x' on complete hydrolysis produced glycine (Gly), alanine (Ala), valine (Val), leucine (Leu) in equimolar proportion each. The number of tetrapeptides (sequences) possible involving each of these amino acids is

Options
  1. a

    16

  2. b

    32

  3. c

    8

  4. d

    24

Correct Answerd

24

Detailed Solution

Step 1: Permutation Rule — A tetrapeptide with four distinct amino acids can be visualized as an arrangement of four unique items in a row.

Step 2: Calculating Sequences — The total number of possible sequences is given by the factorial of the number of amino acids: 4!=4×3×2×1=244! = 4 \times 3 \times 2 \times 1 = 24.

Step 3: Result — Therefore, there are 24 possible unique tetrapeptides involving these four amino acids used exactly once. Correct option is (d).

Common Mistake: Forgetting that if an amino acid is repeated, the number of permutations would decrease.

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A tetrapeptide 'x' on complete hydrolysis produced glycine (Gly), alanine (Ala), valine (Val),… (JEE Main 2023) | Canvas Classes